如果您正在使用apache-commons

public static byte[] toByteArray(int value) {
    byte result[] = new byte[4];
    return Conversion.intToByteArray(value, 0, result, 0, 4);
}

org.apache.hadoop.hbase.util.Bytes类有很多方便的byte[]转换方法，但是你可能不想仅仅为了这个目的就把整个HBase jar添加到你的项目中。令人惊讶的是，这种方法不仅在JDK中缺少AFAIK，而且在明显的库中也缺少AFAIK，比如commons io。

使用Java NIO的ByteBuffer非常简单:

byte[] bytes = ByteBuffer.allocate(4).putInt(1695609641).array();

for (byte b : bytes) {
   System.out.format("0x%x ", b);
}

输出:

0x65 0x10 0xf3 0x29 

public static byte[] intToBytes(int x) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    DataOutputStream out = new DataOutputStream(bos);
    out.writeInt(x);
    out.close();
    byte[] int_bytes = bos.toByteArray();
    bos.close();
    return int_bytes;
}

下面的块至少可以在UDP上发送int。

Int到字节数组:

public byte[] intToBytes(int my_int) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutput out = new ObjectOutputStream(bos);
    out.writeInt(my_int);
    out.close();
    byte[] int_bytes = bos.toByteArray();
    bos.close();
    return int_bytes;
}

字节数组到int:

public int bytesToInt(byte[] int_bytes) throws IOException {
    ByteArrayInputStream bis = new ByteArrayInputStream(int_bytes);
    ObjectInputStream ois = new ObjectInputStream(bis);
    int my_int = ois.readInt();
    ois.close();
    return my_int;
}

byte[] conv = new byte[4];
conv[3] = (byte) input & 0xff;
input >>= 8;
conv[2] = (byte) input & 0xff;
input >>= 8;
conv[1] = (byte) input & 0xff;
input >>= 8;
conv[0] = (byte) input;